Currently, one observes a wide use of automated test equipment (Automated Test Equipment—ATE) to test one or several electrical devices, and to ensure that a series of specific switching sequences or combinations is observed. The automation of the test process making use of these devices brings several advantages to the development process, allowing to minimize inaccuracies and eliminate errors due to human factors.
In the context of electrical test systems for equipment, subassemblies, electronic cards or wiring, ATEs comprising switching matrices are used with the purpose of directing several signals and power to different points on the devices to test.
Known solutions showed to involve significant manual intervention, for instance, the electrical validation of a wiring might take days or even weeks, depending on its dimension and quantity of errors that the test system may identify.
Moreover, in some cases they present slow switching and the wear thereof, resulting from the use of its components. In such circumstances, it becomes mandatory to periodically replace all or part of the components on the switching matrix, for example due to an operation failure or due to a significant drift from its initial specifications, with consequences on the tests performed.
It is also observed an undesirable competitive relation between the switching frequency range and the operation voltage range permitted: a solution that reaches high switching rates, only allows low voltage tests; while a solution allowing high voltage tests can only reach low switching rates.
In what concerns existing disclosures of the state of the art, document U.S. Pat. No. 7,053,624 B2 generally describes a test system for protection relays and their surroundings, namely the different characteristics and conditions where the simulation might occur.
In document U.S. Pat. No. 8,299,798 B2 described is a system having the objective of evaluating the state of relays and in particular arrays of relays, as switching matrices, aiming at isolating and identifying failures using elaborated algorithms. The whole document is focused on the test of relays in the context of groups of relays, making use of switching matrices, with the purpose of isolating the failures in an efficient way.
The document U.S. Pat. No. 9,165,735 B2 describes also a test system that, instead of using simple relays as switches of the switching matrix(ces), uses “compound switches” consisting in the association of electromechanical relays with solid-state relays (“optoMOSFET”) in order to create a more robust and enduring switch. The state change of the contact of the “compound switch” is carried out in a sequential and timed way as described in the various contexts, involving a more complex control system. Furthermore, and in a real context with thousands of test points, this solution shows some disadvantages related to the fact that this is an approach requiring much more space, which is normally very limited, since it requires a control system to manage the sequence and timing of each state change of the contact, the intrinsic wear of the switches and switching time of the electromechanical relays, and due to the associated added cost.